Trawl door



Jan. 26, 1932. R. F'. sYMoNDs TRAWL DOOR Filed Dec. 26, 1925 ooO0OOOOo\ Patented Jan. 26, 1932 UNTE STATES :RALPH F. SYMONDS, I? MARBLEHEAD, MASSACHUSETTS TRAWL DOOR Application 'filed December 26, 1925. Serial No. I77,811.

My invention relates to doors such as are used for keeping the mouth of a trawl net open while it is being towed, and is intended to provide a trawl door which, as compared t with prior doors, will be stronger and more du able, will tow more easily, will be less liable to catch on obstructions, and will be reversible in the sense that it can be readily adapted for use either as the right-hand or the left-hand door of a pair.

rlhe features in which my invention resides are hereinafter described in connection with the accompanying drawings, in whichw Figure 1 is a front view of my door as preferably constructed, the structural parts on the back of the door being shown in dotted lines;

Figure Q is a transverse section on the line .2*2 in Figure l; and

Figure 3 is a diagrammatic view on a smaller scale, illustrating a pair of the doors, with the net and the towing connections attached.

The door illustrated comprises a body portion 2 preferably made of sheet steel and provided on its back or outer face with reinforcing structure riveted or otherwise secured 'thereto and including a pair of longitudinally-extending angle irons 3, located at a distance from the upper and lower edges of the door, and diagonal angle irons each entend ing from one end of one ofthe angle irons 3 to the adjacent corner of the door. Metal strips 5 bolted to the rcarwardlyeextending webs of the respective angle irons El and serve to connect and stillen the latter, and the door may be stitfencd vertically by means of a pair of vertical angle irons G located at the ends of the angle irons 3. The lower edge of the door is provided with a sheet steel 4 shoe 7 which is riveted or otherwise secured to one face of the door, preferably he front face, and extends downwardly and rearv-,fard-- ly therefrom so that it slants away from the direction of drag, as shown in Figure 2,

The towing bracket consists, in the construction illustrated, ot a pair of bracket members 8 and 9, each of which has in eral the form of a broad l! with an eye at the angle of the V and has its free ends bont vtoward each other in the same straight line to serve as pivots. rlhe ends of the rear bracket member 8 are mounted in vertical bearings l0 located on the front face of the door at its longitudinal center and secured thereto by bolts or the like passing through the body portion 2 and 'the angle irons 8. The front bracket member 9 which acts as a strut, has its ends mounted in vertical bearings 11 secured to the door between its front edge and the bearings 10 in such position that the eyes in the two bracket members may be swung together and connected by means of a removable shackle 12, to which the towing cable 13 is attached.

The attachment of the net to the door is provided for by means of a pair of shackles let located respectively at the rear corners of the door and each mounted on a pin 'l5 which passes through the body portion 2 and the adjacent angle iron 4l. rl`he perforations 16 formed in the body portion 2 adjacent to its upper corners provide for the attachment of buffers such as are customarily used to protec-t the sides of the trawling vessel when the door is hauled in.

It will be observed that the door above described is symmetrical with respect to its ends, so that in order to make it reversible and thus enable it to be used either as a right-hand er a lefthand door it is necessary merely to shift the bearings for the bracket member 9 to the opposite side of the center bearings 1G, and to this end the bearings 11 are made detachable and perforations are provided for the reception of the attaching bolts in either position of the bracket, a pair of these perforations being shown at 17. When the door is reversed it is of course necessary to shift the connections to the not also, and provision is made for doing this by forming a perforation 18 in the outer end of each angle iron to receive the pivot on which the corresponding shackle 12 is mounted.

Figure 3 shows a pair of the doors with a net, 19, and the two branches of the towing cable 1B attached to the brackets on the respective doors. While the net is being towed the towing strain is taken up by the reinforcing structure above described, to which the towing cable and the net are attached, and

the only substantial strain on the body portion is that due to the water pressure, of which the lateral component acts on the two doors to force the latterapart and thereby keep the mouth of the net open. Because of its downward and rearward slant the shoe at the bottomofthe door rides lreadily overiordinary obstacles and is not liable to dig into f the sea bottom, so that the door tows more easily than prior doors and its spreading action on the mout-hof the n-'etsis-'less-subject fto r disturbance by variations in the strains aplied to the door. The shoe is also moredura-f f' le than those heretofore employed because of its greater area, over which the wear is'dis- -t-iibiited, and if necessary V'it can be removed and Areplaced by another.

In addition to :the foregoing advantages,i

y.the construction is such that the entire body ofthe door canbe made of steel, resulting in much greater .strength and-durability thanl -is possible in the caseofthe usual-wooden door, and towing connections other than the -form of bracket described-may be readily substituted for thelatter if desired. These Achart acter-istics, .together with ,the reversibility of -be.modiiied in various-.ways ywithout losing ythese.l advantages orideparting fronrmy inthe door,- substantia'lly increase its utility `as i. compared withV prior doors, and; it-will be evident that the details of constructionmay f vention as defined in theisubj oined claims.

` -at eitherrofits ends, and towing connections :located onthe `front faceof the body poi-- I claim:

1. A trawl door comprising a body portion having provisions for attaching a-netathereto tion, said -connectionsbeing reversible lwith respectto the ends of the door.

2. A trawl door providedonits fiont face withv a towing bracket comprising two-meinbers,.one of which is pivoted on a vertical axis located at the longitudinalcenter of the door,

and means forY detachably -pivoting ther other member to .the-doorbetween either end. of the latter and its longitudinal center, said bracket members-beingprovided-with means for attaching the towing cabletoboth .ofi them when swungtogether.

3. A ytrawl door comprising a body portion,

a reinforcing structure secured to its back face, a .towing bracket located -on the front face ofthe body por-tiony and comprising two members each adaptedto swing on. a vertical axis, bearings for one of said members located at the longitudinal center ofthe body portion and connected through the latterto the reinforcing structure, and bearings for :the-other member adapted to be detachably secured to the body portion between either end` of the ylatter and its'longitudina-l center, said bracket members `being provided with means for attaching the towing cableto both of themwhen swung together.

i 4. A .trawlidoor comprising a body portion,

a reinforcing structure secured to its back face, a towing bracket located on the front face of the body portion and connected through the latter to the reinforcing structure, said towing bracket being reversible with respect to the ends of the door, and provisions vfor. attaching anet to ,thedoorat either of its ends.

5. A trawl'door comprising a body portion, a reinforcing structure secured to its back face `and extending:v =tofeachv1f1the four corners thereof, a towing bracket located on the front face of the body portion and connected through the latter to the reinforcing structure, said' towing 'bracket being reversible with respect tothe-ends of thezdoor, andp-provisions for attaching the net toithereinforc- Vmembersrof the reinforcing-structure,by connections passing throughithez-body portion.

Signed at Boston, Massachusetts, this2lst y.day-0f December, 1925.

RALPH FI@ SYMONDS.

3&100 

